This invention relates to a supporting and guiding means for cast strands, in particular cast slabs, in a continuous casting plant having a number of exchangeable supporting elements, which supporting elements are provided with rollers at opposite sides thereof.
The strand emerging from the mould and having a strand skin of only very slight thickness must be supported and guided over a great length. The supporting and guiding means provided therefor has a correspondingly great longitudinal extension and is sub-divided into a number of individually removable and exchangeable supporting elements because of its great own weight and the manipulation difficulties resulting therefrom.
From German Pat. No. 1,285,095, e.g., it is known to divide the supporting and guiding means perpendicular to the axis of the strand path to form supporting elements that can be handled more easily. The supporting elements arranged one behind the other in the longitudinal direction of the strand must be carefully aligned relative to one another for obtaining a satisfying quality of the strand, especially in bow-type continuous casting plants. It is particularly detrimental to the quality of the strand if neighbouring supporting elements are offset relative to each other and thus the roller path is no longer continuous, but has discontinuities. Beside a quality impairment, these discontinuities can cause a great increase in the extraction forces and pronounced deformations of the strand skin, whereby even cracks can form in the strand skin.
For carrying out repairs, the damaged supporting element usually is not repaired at its place of installation, but is removed from the plant, transported to a repair stand and replaced by an intact supporting element that has already been adjusted to the strand thickness desired. In this manner, the facility downtime is kept as short as possible. It has been shown, however, that position control as well as the precise alignment of the newly inserted supporting element relative to the strand guide path formed by the remaining supporting elements, is very difficult. Thereby most of the time gained by the exchange-repair method is lost again.
Furthermore it is necessary to check the position of the supporting elements within short intervals, at the beginning of each shift for instance, in order to detect any damage before the quality of the strand is adversely affected. Hitherto this has not been possible because of the great amount of time needed for such a check-up.